The present invention relates to a delivery device for delivering sheets of paper one at a time by the frictional contact with the front sheet of a stack of sheets of paper which are stored in an aligned or registered relationship.
In a delivery device for taking out sheets one at a time from a stack of sheets of paper stored in an aligned or registered relationship to carry out the processes of counting, discriminating, discharging or the like of sheets of paper such as bank notes, in general a friction roller is brought into frictional contact with the surface of the front sheet and the sheets are delivered by the rotation of the friction roller one at a time.
When the friction roller is used to deliver the sheets as described above, each sheet contacts tangentially the peripheral surface of the friction roller. Therefore, there arises no serious problem in the case of new bank notes because they have uniform surfaces, respectively, but in the case of used bank notes having wrinkles and creases, their surface conditions vary from one to another to cause the bank notes to be slipped and the delivery of them becomes unstable. Especially when the delivered bank notes must be spaced apart from each other by a predetermined distance, the distances between them vary from one to another whereby the successive processes are adversely affected.
In order to ensure the reliable delivery of the sheets, there has been used a delivery device in which a suction head is used to separate one sheet at a time by suction and thereafter the separated sheet is delivered by transport means to the successive processing part of the coin processing machine.
In the case of the delivery device using the suction head described above, it is necessary to cause the suction head to be swung in order to separate the front sheet from the stacked sheets after it is sucked on the sucking surface of the suction head. As a result, there arise the problems that the construction of the delivery device is considerably complicated and that the cost is very expensive because a vacuum pump, a line system for the vacuum pump and associated components such as control valves are required. When the suction head is used, the operation of the control valves becomes inevitably necessary in order to swing and evacuate the suction head. Accordingly, sheet delivery efficiency is inevitably limited.